The identifiers for the Office apps, such as Word and Outlook, can be used for Office for Mac (from an Office 365 or Microsoft 365 subscription plan) or for Office 2019 for Mac (either a retail or a volume licensed version). out of Office 2007-a substantial version upgrade over the previous versions of Office. The subfolder varies depending on your Office version: Office 2016 / 2019: C:\Program Files\Microsoft Office\Office16 or C:\Program Files (x86)\Microsoft Office\Office16 Found inside – First, place the required textbook information outside the CMS. Note: I had two keys listed one was the valid MAK key and one was an Office 16, RETAIL(Grace) channel key. So in your case, you would install Office 2004 and the first time you opened a 2004 application, it would ask for the serial number (which you have) and then the Office 98 CD (which I guess you don't have).